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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54632 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIaMR-0008GO-GT for qemu-devel@archiver.kernel.org; Wed, 16 Sep 2020 12:32:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55052) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIaKe-0006vA-A2 for qemu-devel@nongnu.org; Wed, 16 Sep 2020 12:30:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:38196) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kIaKY-0001YM-Rl for qemu-devel@nongnu.org; Wed, 16 Sep 2020 12:30:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600273844; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8Q79iL6esAeHPH+Xsc3oGIUlFk5qdmvEwHXl8raDgRA=; b=ITPmYmUZjygiYpm4U4ZEtBVoMA3/XOPg4JSdLhIkUdVHlpC4jCnUZ5+DFEUfmkjgbFhJJd 7LIxsqsecjNGLNu1NthLycssSm44cFWC8TC8MdUabI3GcsIXSDefuGYch/tvXP5A/GKGm0 0wi3CDI3HFBdjg+l+KzHnberfON/q+k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-102-aKZO0DU1M6qAbDN9fnMtHA-1; Wed, 16 Sep 2020 12:30:37 -0400 X-MC-Unique: aKZO0DU1M6qAbDN9fnMtHA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9D295801AED for ; Wed, 16 Sep 2020 16:30:36 +0000 (UTC) Received: from redhat.com (ovpn-113-248.ams2.redhat.com [10.36.113.248]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0A8805DEA7; Wed, 16 Sep 2020 16:30:30 +0000 (UTC) Date: Wed, 16 Sep 2020 17:30:27 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Laszlo Ersek Subject: Re: [PATCH] hw/nvram/fw_cfg: fix FWCfgDataGeneratorClass::get_data() consumption Message-ID: <20200916163027.GS1535709@redhat.com> References: <20200916151510.22767-1-lersek@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200916151510.22767-1-lersek@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/16 02:35:56 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.999, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Sep 16, 2020 at 05:15:10PM +0200, Laszlo Ersek wrote: > The documentation on g_byte_array_free() > > says: > > > Returns > > > > the element data if free_segment is FALSE, otherwise NULL. The element > > data should be freed using g_free(). > > Because we currently call g_byte_array_free() with free_segment=TRUE, we > end up passing data=NULL to fw_cfg_add_file(). > > On the plus side, fw_cfg_data_read() and fw_cfg_dma_transfer() both deal > with NULL data gracefully: QEMU does not crash when the guest reads such > an item, the guest just gets a properly sized, but zero-filled blob. > > However, the bug breaks UEFI HTTPS boot, as the IANA_TLS_CIPHER array, > generated otherwise correctly by the "tls-cipher-suites" object, is in > effect replaced with a zero blob. > > Fix the issue by passing free_segment=FALSE to g_byte_array_free(): > > - the caller (fw_cfg_add_from_generator()) temporarily assumes ownership > of the generated byte array, > > - then ownership of the byte array is transfered to fw_cfg, as > fw_cfg_add_file() links (not copies) "data" into fw_cfg. > > Cc: "Daniel P. Berrangé" > Cc: "Philippe Mathieu-Daudé" > Cc: Gerd Hoffmann > Fixes: 3203148917d035b09f71986ac2eaa19a352d6d9d > Signed-off-by: Laszlo Ersek > --- > hw/nvram/fw_cfg.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Daniel P. Berrangé Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|